The Changing Landscape of Concussion

Balance issues are more common in the first two weeks following a concussion than cognitive impairments (Karr, Areshenkoff, & Garcia-Barrera, 2014). Thus, physical therapists are a vital member of the rehabilitation team treating concussion for both assessment and recovery. Also of interest is that abnormal heel-to-toe (tandem) and feet together with eyes closed (Romberg) testing at 2-3 weeks correlates with poor neuropsychological testing related to poor effort and/or invalid test results. Studies have found invalid test performance in adolescent/teens has been shown to occur in 15% of those engaging in neuropsychological testing following concussion (Baker, Connery, Kirk, & Kirkwood, 2014) for a variety of reasons (e.g., school avoidance, athletic team avoidance, family factors, etc.). With increasing use of accelerometers and force plate technology to measure postural control, it is possible to increase validity indicators in the tests used by physical therapists, compared to current methods similar to neuropsychology.

 Questionable testing performances aside, a goal of all medical and rehabilitation providers is for patients to have a quick resolution of symptoms and return to normal life activities following concussion to avoid evolution of post-concussive syndrome (PCS). Given that symptoms of concussion are non-specific in nature and diagnosis remains clinical (no definitive objective test), ongoing neuropsychological research is highlighting the importance of consideration of individuals who meet ICD-10 criteria for PCS pre-injury (including those with no history of concussion)! This has been estimated to be approximately 25% in adolescent male athletes and 35% in adolescent female athletes, with notably higher prevalence rates with individuals who have a history of neurodevelopmental disorders (e.g., ADHD), mental health history (e.g., anxiety), or history of substance abuse (Iverson et al., 2015). Indeed, a recent comprehensive systematic review of the literature has demonstrated that mental health history is the best predictor of outcome in concussion, and loss of consciousness and post-traumatic amnesia do not reliably predict outcome (Iverson et al. 2017).

 In addition to premorbid factors (particularly mental health), concomitant factors related to concussion that are vital to consider for optimal outcome are post-injury behavioral withdrawal (decrease in physical, academic, social/recreational activities) and sleep dysregulation. Relatedly, prolonged rest recommendations (or medically advised behavioral withdrawal) we now understand have historically been based upon expert opinion without any supporting evidence, and are in fact harmful (DiFazio et al., 2016). Telling patients to engage in prolonged rest communicates the expectation of prolonged symptoms (nocebo effect) and prolonged rest in all medical populations can induce depressive symptoms (activity restriction model of depression), which has notable syndromic overlap with the non-specific symptoms of concussion (DiFazio et al., 2016). The best outcomes following concussion are gradual/graded return to normal life activities following 2-3 days of rest (DiFazio et al., 2016). In fact, no literature exists suggesting thinking, reading, or studying can cause neurometabolic demands that are actually harmful to the brain (DiFazio et al., 2016). This early activity resumption includes physical activity resulting in better outcomes following concussion (Grool et al., 2016). Further, poor sleep quality is generally common in youth today due to a variety of factors (e.g., nighttime electronic use), and has been shown to increase risk of concussion (e.g., poorer balance, proprioception, attention, etc.; e.g., Kim et al., 2015), as well as become dysregulated following concussion leading to an increase in symptoms, such as a three fold increase in the most common symptom of concussion, headaches (Chaput, Figuere, Chauny, Denis, & Lavigne, 2009). Many other neuropsychological factors are important to consider (e.g., parental anxiety or distress) in concussion management, and even a one-time consultation with neuropsychology has demonstrated significant decrease in PCS symptoms within one week to several months later (Kirkwood et al., 2016). This speaks to the importance of a multidisciplinary approach to concussion for comprehensive and robust management and prevention of evolution of PCS. 

Author: Tyler  Duffield, PhD